Question

1. Wegener formed the theory of continental drift in 1912. What prevented research of the ocean floor, paleomagnetism, and earthquakes at that time?

Answer 1

This explanation and his theory were not widely accepted. Prior to Wegener, however, many had noted that the shapes of the continents seem to fit together, suggesting some schism in the past. 

Continental drift was really not allowable as even an accepted theory until the 1950s. Most geologists accepted the theory as quite possible before 1970. Several factors point to the acceptance of the continental drift theory. 

Fossil records from separate continents, particularly on the outskirts of continents show the same species. As well mineral specimens along the supposed break lines of the continents are nearly identical. Some identical species exist on certain continents, like an earthworm common to both Africa and South America suggesting the species could not have spontaneously arisen on both continents without some variations hope this helps

Answer 2

It was not accepted during Wegener's lifetime because, mainstream scientists that time didn't know the mantle was liquid, they thought it was solid.  They thought the throry was illegitimate because continents did not fit exactly together.

The evidence supporting Wegener's theory was all discovered after his lifetime, like the Seismographs revealed a pattern of volcanoes and earthquakes, and Radiometric dating of rocks revealed a surprisingly young oceanic crust.